import java.util.Scanner;

public class demo01 {
    public static void main(String[] args) {
        Scanner sc=new Scanner(System.in);
        while (sc.hasNext()){
            int n=sc.nextInt();
            int m=2*n-1;
            int[][] arr=new int[n][m];
            for (int i = 0; i < n; i++) {
                for (int j = 0; j < m; j++) {
                    arr[i][j]=0;
                }
            }
            arr[0][0]=1;
            for (int i = 1; i < n; i++) {
                arr[i][0]=1;
                arr[i][2*i]=1;
                for (int j = 1; j < 2*i; j++) {
                    if(j==1){
                        arr[i][j]=arr[i-1][j]+arr[i-1][j-1];
                    }else {
                        arr[i][j]=arr[i-1][j]+arr[i-1][j-1]+arr[i-1][j-2];
                    }
                }
            }
            int k=0;
            for (; k < m; k++) {
                if(arr[n-1][k]%2==0){
                    System.out.println(k+1);
                    break;
                }
            }
            if(k==m){
                System.out.println(-1);
            }
        }
    }
}
